docs: def _dispatcher(self, connection, event):
          """
          Dispatch events to on_<event.type> method, if present.
          """
          log.debug("_dispatcher: %s", event.type)
  
          def do_nothing(connection, event):
              return None
          method = getattr(self, "on_" + event.type, do_nothing)
          method(connection, event)